Hard to tell. The anime is closer to the manga. The movie leaves a lot out. Depends if you like to watch the movie with the mindset, to constantly compare in your mind what is left out and what they changed. On the other hand if you watch the movie first and then the anime, you already know the basic gist but have to watch it dragged out (although with a lot of additional stuff) over 26 episodes.
I would say it's a similar beast as with Death Note. Which adaption would you have liked to seen first there?
Also you have to consider, that I have read the manga first, then seen the anime and the movie last. It's hard for me to say how the movie would come across for people not knowing the source material. Dave seemed to have enjoyed it.